Mean Cerebrospinal Fluid Opening Pressure Research Articles

Comparison of Optic Nerve Sheath Diameter (ONSD) Measurements Obtained from USG Before and After Placement of Ventriculoperitoneal Shunt in Obstructive Hydrocephalus as a Surrogate Marker for Adequacy of Shunt Function: A Prospective Observational Study

Abstract Introduction Optic nerve sheath diameter (ONSD) measured using ultrasonography has been widely used as a surrogate marker of elevated intracranial pressure. However, literature is sparse on the correlation between ONSD and ventriculoperitoneal (VP) shunt function, especially in adults with hydrocephalus. Our study was designed to assess the correlation between ONSD measured using ultrasonography before and 12 hours after VP shunt placement and the success of VP shunt placement assessed using computed tomography (CT) of the brain. Materials and Methods Fifty-one patients between 16 and 60 years of age, with obstructive hydrocephalus scheduled for VP shunt surgery were included in this prospective, observational study. ONSD measurements were obtained from both eyes prior to induction of anesthesia, immediately after the surgery, and at 6, 12, and 24 hours after the surgery. An average of three readings was obtained from each eye. Cerebrospinal fluid (CSF) opening pressure was noted after entry into the lateral ventricle. Noncontrast CT (NCCT) brain was obtained 12 hours after the surgery and was interpreted by the same neurosurgeon for signs of successful VP shunt placement. Results There was a significant reduction in ONSD in the postoperative period compared to ONSD measured preoperatively. The average ONSD (mean ± standard deviation) measured prior to induction of anesthesia, immediately after the surgery, and at 6, 12, and 24 hours after the surgery was 5.71 ± 0.95, 5.20 ± 0.84, 5.06 ± 0.79, 4.90 ± 0.79, and 4.76 ± 0.75 mm, respectively. The mean CSF opening pressure was 19.6 ± 6.9 mm Hg. Postoperative NCCT brain revealed misplacement of the shunt tip in only one patient. Conclusion ONSD measured using ultrasonography may be used as a reliable indicator of VP shunt function in adults with obstructive hydrocephalus.

Neurologic Deficits and cerebrospinal fluid (CSF) lymphocytosis (HaNDL): a comprehensive systematic review of 93 patients from 57 studies (P3-12.003)

<h3>Objective:</h3> N/A <h3>Background:</h3> Headache with Neurologic Deficits and cerebrospinal fluid (CSF) lymphocytosis (HaNDL) is a self-limiting syndrome characterized by moderate to severe headache associated with focal neurological deficits such as, motor or sensory deficits, or speech disturbances, occurring in the context of lymphocytosis in the cerebrospinal fluid. Due to being a rare condition, data regarding HaNDL is sparse. Therefore, we conducted this review to analyze data related to 93 patients of HaNDL, to characterize their demographics, wide range of presenting symptoms, treatment options in the acute and chronic phases, EEG, brain imaging and CSF findings. <h3>Design/Methods:</h3> We performed a systematic review of cases reported through PubMed and Google scholar database, using Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. <h3>Results:</h3> The mean age was 28.8 years at onset. 70 patients (75.2%) were adults, while 23 (24.7%) were pediatrics. 30% of patients experienced relapsing episodes of HaNDL symptoms. The most common type of headache reported was unilateral severe throbbing episodic headache. Other associated symptoms included sensory deficit (60%) and motor deficits (54.8%). The least common symptoms were nystagmus and agraphia. Antiviral agents were a common treatment option in the acute phase [n=23 patients (23.6%)], while Flunarizine was the most commonly used agent in the chronic setting [n= 3 patients (3.2%)]. The most common brain MRI findings included nonspecific white matter lesions and meningeal enhancement, whereas the most common EEG findings include diffuse and focal slowing. The mean CSF opening pressure was 240.5 mmH2O. CSF protein was elevated in 59 patients , with a mean value of 114mg/dL. <h3>Conclusions:</h3> HaNDL tends to affect young individuals with a slight male predominance. Unilateral severe throbbing episodic headache with associated hemi-paresthesia and hemiparesis were the most common presenting symptoms based on our review. Early recognition of this syndrome is critical in order to prevent unnecessary treatments such as, antimicrobials. <b>Disclosure:</b> Mr. Asghar has nothing to disclose. Mr. Asghar has nothing to disclose. Mr. Hegde has nothing to disclose. Mr. Delcimmuto has nothing to disclose. Dr. Gharaibeh has nothing to disclose. Dr. Aladamat has nothing to disclose. Dr. Esengul has nothing to disclose. Mohammad Mahmoud Samara, MD has nothing to disclose. Dr. Sheikh has nothing to disclose.

Clinical profile and ophthalmological manifestations of idiopathic intracranial hypertension in adults at a tertiary care center in India: A cross-sectional study.

Our aim was to describe the clinical profile of patients with idiopathic intracranial hypertension (IIH), assess ophthalmological manifestations, and correlate grade of papilledema with optic nerve sheath diameter (ONSD) and cerebrospinal fluid (CSF) opening pressure. This was a prospective cross-sectional study. Patients between 18 and 60 years, diagnosed with IIH using modified Dandy criteria were included. Demographic details, ocular symptoms and signs were noted and papilledema graded. Ocular investigations such as B-scan ONSD and perimetry findings were noted for analysis. The study included 32 patients of mean age 35.25(±9.57) years with a predominantly female population (96.9%). Mean BMI was 28.12(±5.32) kg/m2. Common presenting complaint was headache (87.5%). The most common gynecological disorder was dysmenorrhea (15.6%). Vitamin D deficiency (46.9%) was a biochemical abnormality seen. Most patients had BCVA 6/6 (62.5%). Lateral rectus palsy was present in 12.5%. Papilledema was present in 81.3% eyes with 31.3% Grade I. There was visual field loss in 53.1%, with 20.3% Grade I. Mean CSF opening pressure was 376.3(±191.51) mmH2O. MRI showed empty sella (34.4%) and tortuous optic nerve (18.8%). MRV showed transverse sinus stenosis (52.4%) as common abnormality. There was significant correlation between grade of papilledema and B-scan ONSD. No correlation was seen between CSF opening pressure and ONSD, grade of papilledema and grade of visual field defect and CSF opening pressure with BMI. Clinical profile of patients with IIH was an overweight female of child-bearing age with headache. Visual field examinations are essential in management and follow-up. B-scan ONSD is useful to quantify raised ICP.

Comparison of Optic Nerve Sheath Diameters Measured by Optic Ultrasonography Before and After Lumbar Puncture in Idiopathic Intracranial Hypertension Patients.

Idiopathic intracranial hypertension (IIH) symptoms include headache, blurred vision, and papilledema which may lead to permanent vision loss unless diagnosed and treated. Definitive diagnosis of IIH usually requires the measurement of intracranial pressure (ICP) via lumbar puncture (LP) which is an invasive and unwanted technique for patients. In our study, optic nerve sheath diameters (ONSD) were measured before and after lumbar puncture in IIH patients and the relationship of these measurements with ICP changes was evaluated as well as the effect of decreasing cerebrospinal fluid (CSF) pressure after a lumbar puncture on ONSD. Thus, we want to investigate whether optic nerve ultrasonography (USG) is a useful tool instead of the invasive LP for the diagnosis of IIH. A total of 25 patients who applied to the neurology clinics of Ankara Numune Training and Research Hospital between May 2014 and December 2015 and were diagnosed with IIH were included in the study. The control group consisted of 22 individuals who applied with complaints other than headaches, visual impairment or tinnitus. Optic nerve sheath diameters were measured from both eyes before and after the LP. After pre-LP measurements were taken, opening and closing CSF pressure was measured. In the control group, ONSD was measured with optic USG. Mean age of the IIH group and the control group was determined as 34.8±11.5 and 45.8±13.3 years, respectively. In the patient group, mean CSF opening pressure was 33.9±8.0 cm H2O and mean closing pressure was 18.1±4.7 cm H2O. Mean ONSD measured pre-LP was 7.1±1.0 mm in the right eye and 6.9±0.7 mm in the left eye, while mean post-LP ONSD was 6.7±0.9 mm in the right eye and 6.4±0.8 mm in the left eye. There was a statistically significant difference between ONSD values before and after the LP (p=0.006 for the right eye, p<0.001 for the left eye). In the control group, mean ONSD was 5.4±0.7 mm in the right eye and 5.5±0.6 mm in the left eye, and a statistically significant difference was found between ONSD values before and after the LP (p<0.001 for the right eye and left eye). A significant positive correlation was determined between left ONSD measurements before the LP and CSF opening pressure (r=0.501, p=0.011). In the present study, it was found that ONSD measurement by optic USG significantly displays increased ICP, and decreasing pressure via LP is rapidly reflecting ONSD measurement. Based on these findings, it is suggested that ONSD measurements by optic USG, a non-invasive method, can be used in the diagnosis and follow-up of IIH patients.

Correlation of palpation anterior fontanometry and cerebrospinal fluid opening pressure in early childhood hydrocephalus.

The anterior fontanelle (AF) tension has been a traditional clinical method of indirect assessment of intracranial pressure (ICP). How does this time-tested bedside assessment technique compare with an objective ventricular cerebrospinal fluid (CSF) opening pressure? To determine the correlation of palpation anterior fontanometry and CSF opening pressure in early childhood hydrocephalus. Children diagnosed with hydrocephalus who were planned for CSF diversion using ventriculo-peritoneal (V-P) shunt were prospectively studied over 18 months. The AF tension was assessed by palpation preoperatively and graded. The CSF opening pressure was measured using sterile disposable plastic manometers after ventricular cannulation intraoperatively. Data obtained were analysed using SPSS version 21. Student's t-test, Mann-Whitney U test and ANOVA were used to determine associations based on normality tests. A P < 0.05 was considered significant for associations. Fifty-two children were operated on with AF patency rate of 88.5%. Their age ranged between 2 weeks and 18 months with a mean age of 7.1 ± 5.1 months. The fontanelle tension was tense, full and normal in 63.0%, 26.1% and 10.9% of patients, respectively. The mean CSF opening pressure of 20.5 ± 8.5 cm of H2O was higher than the expected ICP for the age group (t-test 4.754, P = 0.000). All 28 patients with CSF opening pressure >15 cm of H2O had a tense fontanelle, but 10.9% of children with raised ICP have normal AF tension. The mean ICP increases as palpation AF tension increases, but a normal AF tension does not rule out raised ICP.

Optic nerve ultrasonography in monitoring treatment efficacy in pediatric idiopathic intracranial hypertension.

Measurement of optic nerve sheath diameter (ONSD) with ocular ultrasonography (USG) is a noninvasive technique that can be readily used to determine clues of increased intracranial pressure. In this study, we aimed to determine the role of optic nerve sheath diameter measurements in the diagnosis and follow-up of pediatric patients with idiopathic intracranial hypertension (IIH). Eight patients with a diagnosis of IIH with a median age of 11.7 (range 4.5-17) years were examined prospectively. During follow-up, orbital ultrasonography (USG) was performed immediately prior to lumbar puncture (LP) and at 24h, at 1week, and between 1 and 18months after LP. Cranial MRI examinations and automated visual field assessments were performed at baseline and at 3months, and both measurements were compared with each other. The mean cerebrospinal fluid opening pressure (37.75 ± 12.64cm H2O) and the mean ONSD (5.94 ± 0.46mm) were correlated. The median follow-up was 16 (range, 12-18months), and ONSD regressed gradually consistent with clinical and radiologic improvement during follow-up. To the best of our knowledge, this is the first prospective pilot study performed on pediatric patients with IIH using orbital USG for ONSD measurements. Despite the small sample size, the present study indicated that orbital USG may be used as a promising noninvasive tool to diagnose increased intracranial pressure and for monitoring treatment efficacy in this special patient population.

Prevalence of new-onset migraine in patients with idiopathic intracranial hypertension in comparison to the general population

Background: Idiopathic intracranial hypertension (IIH) encompasses patients with elevated intracranial pressure (ICP). Generally, it is difficult to make a differential diagnosis between IIH and co-existing migraine headaches. Thus, this article intends to estimate the prevalence of migraine in patients with IIH and explain the occurrence of new-onset migraine after the diagnosis of IIH. Methods: The case group included 108 patients with IIH referred to the neurology wards of three university hospitals. A random sample of controls (n = 103) were recruited from patients hospitalized in the surgery and orthopedics ward. A checklist for migraine diagnosis was filled out. Cerebrospinal fluid (CSF) pressure and presence or absence of papilloedema (PE) in the patients and any necessary data were also recorded from the inpatient medical documents. All statistical analyses were done by SPSS software. Results: There were 70 (64.80%) and 22 (21.40%) migraineurs in the case and control groups, respectively, and the difference was found to be significant (P < 0.001). In 26 (37.14%) migraine cases in the IIH group, the disorder was diagnosed after developing IIH. Also, there was a past medical history of having migraine in 44 (62.85%) migraineurs. In the fully adjusted regression models, the odds of being affected by migraine in patients with IIH was 6.17 times greater than the controls [odds ratio (OR) = 7.15, 95% confidence interval (CI) = 3.56-14.36, P < 0.010]. The patients' mean CSF opening pressure was 32.10 ± 1.03 cmH2O and 93 (81.60%) subjects were found to have PE. Conclusion: It was demonstrated that subjects with IIH might have about a 6-time higher likelihood of developing migraine headache than the general population. These considerations can help prevent misdiagnosis of migraine headache as the recurrence of IIH or uncontrolled IIH and subsequent inappropriate management.

Differing presenting features of idiopathic intracranial hypertension in the UK and US.

Demographic factors potentially influencing the presentation and severity of idiopathic intracranial hypertension (IIH) in the US vs. UK populations include obesity and ethnicity. We aimed to compare the presenting features of IIH between populations in the UK and US tertiary referral centres, to assess what population differences exist and whether these cause different presentations and impact on visual function. Clinical data were collected on 243 consecutive UK IIH patients and 469 consecutive US IIH patients seen after 2012 in two tertiary centres. Visual function was defined as severe visual loss when Humphrey visual field mean deviation was <-15 dB, when Goldmann visual fields showed constriction or when visual acuity was <20/200. US patients were more commonly of self-reported black race (58.9% vs. 7.1%) than UK patients, but had a similar mean body mass index (38.3 ± 0.63kg/m2 UK vs. 37.7 ± 0.42kg/m2 US; p = 0.626). The UK cohort had lower presenting Frisén grade (median 1 vs. 2; p < 0.001) and severe visual loss less frequently (15.4% vs. 5%; p = 0.014), but there was no difference in mean cerebrospinal fluid-opening pressure (CSF-OP) (35.8 ± 0.88cmH2O UK vs. 36.3 ± 0.52cmH2O US; p = 0.582). African Americans had poorer visual outcomes compared with US whites (19.4% vs. 10% severe visual loss; p = 0.011). Visual function was weakly associated with CSF-OP (R2 = 0.059; p = 0.001), which was similar between UK and US patients. The UK and the US cohorts had a similar average presenting BMI. However, the worse presenting visual function in the US IIH cohort was partially attributable to differences in the black populations in the two countries.

Increased Intracranial Pressure in Acute Disseminated Encephalomyelitis

To assess the intracranial pressure in pediatric acute disseminated encephalomyelitis using spinal tap opening pressure on lumbar puncture, which is routinely performed as part of suspected acute disseminated encephalomyelitis workup. Compared to other cerebrospinal fluid parameters such as cell count, protein concentration, and presence of oligoclonal bands, cerebrospinal fluid opening pressure is infrequently recorded. A retrospective chart review of demographic, clinical, and laboratory data of children diagnosed with acute disseminated encephalomyelitis admitted to a tertiary referral hospital between 2005 and 2016. Of the 36 children diagnosed with acute disseminated encephalomyelitis, 24 had the cerebrospinal fluid opening pressure documented in their records. The mean cerebrospinal fluid opening pressure was 27.6±12.6 cmH2O, range 9-55 cmH2O (95% confidence interval 21.9-33.6). Cerebrospinal fluid opening pressure in the acute disseminated encephalomyelitis group was statistically significantly higher ( P = .0013, 95% confidence interval 4.2-15.0) than the accepted upper limit in this age group (18 cmH2O). In 10 of 24 patients (42%), the opening pressure was above 28 cmH2O. Increased opening pressure was the most frequent cerebrospinal fluid abnormal finding in our cohort, which suggests a potential role of increased intracranial pressure in the acute disseminated encephalomyelitis pathophysiological disease mechanism. In certain cases, the opening pressure value could have monitoring and therapeutic implications, and therefore its measurement is highlighted by this study.

Long-term Response of Cerebrospinal Fluid Pressure in Patients with Idiopathic Intracranial Hypertension - A Prospective Observational Study.

Background:Idiopathic intracranial hypertension (IIH) is increased intracranial pressure (ICP) with normal cerebrospinal fluid (CSF) contents, in the absence of an intracranial mass, hydrocephalus, or other identifiable causes. The current knowledge of the treatment outcome of IIH is limited, and the data on the natural history of this entity are scant.Objective:The objective of the study is to study the treatment response of IIH by serially measuring the CSF opening pressure and to delineate the factors influencing the same.Materials and Methods:A prospective observational study in a cohort of fifty patients with IIH in whom CSF opening pressure was serially measured at pre-specified intervals.Results:The mean CSF opening pressure at baseline was 302.4 ± 51.69 mm of H2O (range: 220–410). Even though a higher body mass index (BMI) showed a trend toward a higher CSF opening pressure, the association was not significant (P = 0.168). However, the age of the patient had a significant negative correlation with the CSF pressure (P = 0.006). The maximum reduction in CSF pressure occurred in the first 3 months of treatment, and thereafter it plateaued. Remission was attained in 12 (24%) patients. BMI had the strongest association with remission (P = 0.001).Conclusions:In patients with IIH, treatment response is strongly related to BMI. However, patients with normal BMI are also shown to relapse and hence should have continuous, long-term follow-up. The reduction in CSF pressure attained in the first 3 months could reflect the long-term response to treatment.

Nimotuzumab treatment and outcome analysis in patients with leptomeningeal metastasis from nonsmall cell lung cancer.

Leptomeningeal metastasis (LM) leades a devastating consequence in patients with nonsmall cell lung cancer(NSCLC). Treatment is very limited for patients with LM. We introduced to use nimotuzumab (also known as h-R3) combined with methotrexate for treating LM in NSCLC patients. In the present report, twenty patients with LM of NSCLC were included, and the clinicopathology information and outcomes after treatment were analyzed. All the twenty patients with LM were lung adenocarcinoma. Thirteen patients had poor Eastern Cooperative Oncology Group performance status (≥ 3) before treatment, fifteen patients received combined administration of h-R3 and methotrexate, and another five patients received h-R3 treatment alone. The median survival time after the diagnosis of LM was 5 months (range, 2.4-7.6 months) for these twenty patients. The mean cerebrospinal fluid opening pressure was 270mmH2O before treatment and decreased significantly after treatment (140 mmH2O) (P < 0.001). Associated symptoms were relieved quickly after one or two cycles of intrathecal therapy. These findings indicated that nimotuzumab might be a potential drug for treatment of LM in NSCLC patients.

Cerebrospinal fluid opening pressure measurements in acute headache patients and in patients with either chronic or no pain

To observe cerebrospinal fluid opening pressure (CSFOP) in different clinical settings and in patients with acute, chronic and no pain and to observe possible differences because of age and sex. In this prospective study, CSFOP was measured in lumbar puncture in three different settings of clinical investigations; patients with acute headache investigated for subarachnoidal haemorrhage (n = 222), patients with sciatica undergoing myelography (n = 61), and patients in an outpatient neurological clinic (n = 65). The mean CSFOP in cm H(2)O was 17.3 for the myelography patients, 19.1 for the outpatients, 19.3 for the primary headache patients and 22.4 for the patients with secondary headache. Large proportions of patients in all groups had CSFOP above 20 cm H(2)O. The female patients in all groups had lower mean CSFOP than the male patients. The CSFOP levels found in clinical practice among patients without intracranial lesions or infectious conditions were broader than expected. Measurement of CSFOP is of limited value as diagnostic procedure if not closely linked to clinical symptoms and finds.

Utility of clinical assessment, imaging, and cryptococcal antigen titer to predict AIDS-related complicated forms of cryptococcal meningitis

BackgroundThis study aimed to evaluate the prevalence and predictors of AIDS-related complicated cryptococcal meningitis. The outcome was complicated cryptococcal meningitis: prolonged (≥ 14 days) altered mental status, persistent (≥ 14 days) focal neurologic findings, cerebrospinal fluid (CSF) shunt placement or death. Predictor variable operating characteristics were estimated using receiver operating characteristic curve (ROC) analysis. Multivariate analysis identified independent predictors of the outcome.ResultsFrom 1990-2009, 82 patients with first episode of cryptococcal meningitis were identified. Of these, 14 (17%) met criteria for complicated forms of cryptococcal meningitis (prolonged altered mental status 6, persistent focal neurologic findings 7, CSF surgical shunt placement 8, and death 5). Patients with complicated cryptococcal meningitis had higher frequency of baseline focal neurological findings, head computed tomography (CT) abnormalities, mean CSF opening pressure, and cryptococcal antigen (CRAG) titers in serum and CSF. ROC area of log2 serum and CSF CRAG titers to predict complicated forms of cryptococcal meningitis were comparable, 0.78 (95%CI: 0.66 to 0.90) vs. 0.78 (95% CI: 0.67 to 0.89), respectively (χ2, p = 0.95). The ROC areas to predict the outcomes were similar for CSF pressure and CSF CRAG titers. In a multiple logistic regression model, the following were significant predictors of the outcome: baseline focal neurologic findings, head CT abnormalities and log2 CSF CRAG titer.ConclusionsDuring initial clinical evaluation, a focal neurologic exam, abnormal head CT and large cryptococcal burden measured by CRAG titer are associated with the outcome of complicated cryptococcal meningitis following 2 weeks from antifungal therapy initiation.

Laser scanning tomography measurement of the extent of papilledema in the follow-up examination of patients with idiopathic intracranial hypertension

The authors evaluated the characteristics of patients with idiopathic intracranial hypertension (IIH), and compared laser scanning tomography (LST) measurements of papilledema with the clinical parameters and cerebrospinal fluid (CSF) opening pressures obtained. Twenty-four patients were included in this study; these individuals included 21 women and three men with a mean age of 35.5 +/- 9.7 years and a mean body mass index (BMI) of 35.4 +/- 8.3 kg/m2. The authors conducted a prospective follow-up study over a period of 12 months through a series of four consultations with each patient. These patients had a mean time to treatment of 6.2 +/- 7.9 months and, at the time of diagnosis, suffered a mean of 2.8 +/- 1.3 symptoms each. Laser scanning tomography of the optic disc revealed a mean global rim volume of 1.693 +/- 1.662 mm3 and a mean height of 0.604 +/- 0.306 mm. The mean CSF opening pressure was 31.3 +/- 6.3 cm H2O. During the follow-up period, all patients improved significantly with regard to clinical parameters (p < 0.001), BMI reduction (p < 0.001), and reduction of visual field deficits (p = 0.007); visual acuity remained unchanged. In all patients at each successive consultation, the CSF opening pressure was lower than it had been at the previous consultation (p = 0.001). Laser scanning tomography measurements demonstrated a statistically significant reduction in both optic disc parameters over the follow-up period (global rim volume, p = 0.044; mean height, p = 0.019). The CSF opening pressure and the LST measurements correlated significantly with the number of symptoms (CSF opening pressure, p < 0.001; global rim volume, p = 0.001; mean height, p < 0.001). The mean area under the receiver operating characteristic curve in detecting the presence of clinical symptoms was 0.87 for CSF opening pressure, 0.7 for rim volume, and 0.81 for mean optic disc height. Laser scanning tomography measurements are useful for evaluating the degree of papilledema in patients with IIH and correspond well with clinical data and measurements of CSF opening pressure. If a diagnosis of IIH is established, LST measurements may replace repeated CSF opening pressure measurements in follow-up monitoring.

Ketamine Increases Opening Cerebrospinal Pressure in Children Undergoing Lumbar Puncture

Intravenous ketamine, often administered concomitantly with midazolam, is one of the most commonly used drugs for procedural sedation in children. Although it is considered safe for use in children, ketamine can increase intracranial pressure. Hence, this study was carried out to determine whether adding ketamine to midazolam prior to performing lumbar puncture would be associated with a higher cerebrospinal fluid opening pressure in children with suspected aseptic meningitis. Thirty-nine children aged 6 months to 14 years were included: 26 in group A (intravenous midazolam plus ketamine) and 13 in group B (intravenous midazolam only). Mean cerebrospinal fluid opening pressure in group A was 24.4 cm H2O (median 23 cm H2O) compared with 20 cm H2O (median 19.8 cm H2O) in group B (P = .011). Intravenous ketamine prior to performing lumbar puncture is associated with a significantly higher lumbar cerebrospinal fluid opening pressure in children with aseptic meningitis. However, no outcome differences have been found between the two groups.

The Effect of Lower‐extremity Position on Cerebrospinal Fluid Pressures

To determine the effects of lower-extremity positioning on cerebrospinal fluid opening pressure (CSFp). The authors believed that during lumbar puncture (LP), CSFp does not meaningfully decrease when the lower extremities are extended from flexion, as is often suggested. In a convenience sample of adult patients who clinically required LP in an urban emergency department, three sequential CSFp measurements were obtained in either sequence A (knee, hip, and neck flexion [90 degrees ], then extension, then flexion) or sequence B (extension, flexion, then extension) prior to CSF withdrawal. The neck was flexed at 30 degrees when the lower extremities were flexed, while the thoracolumbar spine was kept in the neutral position for all measurements. Nineteen patients were studied in each sequence. Although variable, overall within-patient changes between positions were not clinically meaningful. Mean and 95% confidence intervals (95% CIs) for the decrease in CSFp from position 1 to position 3 (same position) were 0.2 cm H(2)O (1.7%) and 0.9 to -0.6 cm H(2)O (6% to -2.7%), respectively. Changing from flexion to extension decreased pressure measurements by a mean of 0.9 cm H(2)O (2.5%) [95% CI = 2.1 to -0.1 cm H(2)O (7.6% to -2.4%)]. Changing from extension to flexion increased CSFp by a mean of 1.1 cm H(2)O (6.1%) [95% CI = 0.2 to 2.0 cm H(2)O (1.3% to 11.5%)], a statistically but not clinically meaningful change. Changing lower-extremity position did not meaningfully change mean CSFp. These data do not support the common suggestion that extending the lower extremities during LP meaningfully decreases CSF opening pressures.